Please help! 2002 7.3 Engine Knock

[SafricanPSD]

My engine has suddenly developed a knock today. Sounds like it in or around the valley, and only audible at low RPM, and worst at idle. Lots of white/grey smoke when cold. No knocking or noise other than the usual clatter when driving at highway or city speeds. Just drove from Atlanta to Charlotte without any problems, just this new knocking noise when idling or at low RPM in traffic etc. Worst case it could be a bearing, but could it be the pump or something else? Are there any PSD experts in Charlotte NC that I can go to to have it checked out? Any help will be highly appreciated

you say it is fine when you get your rpms up? I wonder if you dont have an injector hanging open and pouring the fuel in!

[mschn99]

sounds like a bad injector to me....call Trucks Unlimited in Winston-Salem....Scott will get you fixed up right!!!

[bigcountrysg]

If it was a bearing it would get worse at high rpms. I aggree with Jon, but I also would test the Hpop (high pressure oil pump) out. Maybe getting weak and not providing enough pressure at low idle. Or it could be the regular oil pump going weak so it is causing a knock at idle because of low engine oil pressure.

When was the last oil change.

[SafricanPSD]

Thanks for the info guys! Definately no knock at high rpm, and way too much smoke when cold, and white/light grey, not black. Had the oil changed about 2000mi ago, and every 5000mi before that. Bought the truck with 98000mi on it, it's on 115,000mi now. Previous owner told me that the lift pump, not sure which pump that is, was replaced by a dealer at around 75,000mi. Oil pressure according to the guage is good, nearer to high than low, if one can believe the factory guage..

thats just a base oil pressure guage. You have an injector hanging wide open. If you dont want to take it to a dealer you can get ahold of Scott at Trucks Unlimited and we can get your truck fixed. We are in Winston Salem. TU # 336-764-5657

[SafricanPSD]

Tried calling, guess they don't work Saturdays, right? Started it up this morning, did not knock much at idle, and noticed a fair amount of smoke coming from the back around the turbo. On closer inspection found that it was coming from the flange, where the turbo is bolted to the exhaust. Any thoughts?

[fordcummins]

That's an exhaust leak. That's not causing your problem with the knock.

[03PSD7.3]

Possibly with that exhaust leak, where the flange meets up to the turbo it is more than likely loose, possible causing a knocking noise at low rpm's. Just a thought, had the same problem before.

Stephen

[Strokin]

Hey guys, I have a similar problem with my '99 250. When started or when you let off of the accelerator, there is a bad grinding or scratchy sound with a knock also. If I accelerate the engine to about 1200rpm or during normal driving the engine sounds perect as it always has. I have 216,000mi. on the truck with about 400 miles on new oil and filter change. About two weeks ago I had a trouble code associated with the exhaust backpressure sensor (it was reading 52psi,normally should be 14) replaced sensor and stopped-up tube from manifold and everything was reading just fine. The noise started this morning and sounds like something is going to come apart. Any help would be greatly appreciated.